1*0b57cec5SDimitry Andric //=- WebAssemblySetP2AlignOperands.cpp - Set alignments on loads and stores -=// 2*0b57cec5SDimitry Andric // 3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric // 7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric /// 9*0b57cec5SDimitry Andric /// \file 10*0b57cec5SDimitry Andric /// This file sets the p2align operands on load and store instructions. 11*0b57cec5SDimitry Andric /// 12*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 13*0b57cec5SDimitry Andric 14*0b57cec5SDimitry Andric #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" 15*0b57cec5SDimitry Andric #include "WebAssembly.h" 16*0b57cec5SDimitry Andric #include "WebAssemblyInstrInfo.h" 17*0b57cec5SDimitry Andric #include "WebAssemblyMachineFunctionInfo.h" 18*0b57cec5SDimitry Andric #include "llvm/CodeGen/MachineBlockFrequencyInfo.h" 19*0b57cec5SDimitry Andric #include "llvm/CodeGen/MachineMemOperand.h" 20*0b57cec5SDimitry Andric #include "llvm/CodeGen/Passes.h" 21*0b57cec5SDimitry Andric #include "llvm/Support/Debug.h" 22*0b57cec5SDimitry Andric #include "llvm/Support/raw_ostream.h" 23*0b57cec5SDimitry Andric using namespace llvm; 24*0b57cec5SDimitry Andric 25*0b57cec5SDimitry Andric #define DEBUG_TYPE "wasm-set-p2align-operands" 26*0b57cec5SDimitry Andric 27*0b57cec5SDimitry Andric namespace { 28*0b57cec5SDimitry Andric class WebAssemblySetP2AlignOperands final : public MachineFunctionPass { 29*0b57cec5SDimitry Andric public: 30*0b57cec5SDimitry Andric static char ID; // Pass identification, replacement for typeid 31*0b57cec5SDimitry Andric WebAssemblySetP2AlignOperands() : MachineFunctionPass(ID) {} 32*0b57cec5SDimitry Andric 33*0b57cec5SDimitry Andric StringRef getPassName() const override { 34*0b57cec5SDimitry Andric return "WebAssembly Set p2align Operands"; 35*0b57cec5SDimitry Andric } 36*0b57cec5SDimitry Andric 37*0b57cec5SDimitry Andric void getAnalysisUsage(AnalysisUsage &AU) const override { 38*0b57cec5SDimitry Andric AU.setPreservesCFG(); 39*0b57cec5SDimitry Andric AU.addPreserved<MachineBlockFrequencyInfo>(); 40*0b57cec5SDimitry Andric AU.addPreservedID(MachineDominatorsID); 41*0b57cec5SDimitry Andric MachineFunctionPass::getAnalysisUsage(AU); 42*0b57cec5SDimitry Andric } 43*0b57cec5SDimitry Andric 44*0b57cec5SDimitry Andric bool runOnMachineFunction(MachineFunction &MF) override; 45*0b57cec5SDimitry Andric }; 46*0b57cec5SDimitry Andric } // end anonymous namespace 47*0b57cec5SDimitry Andric 48*0b57cec5SDimitry Andric char WebAssemblySetP2AlignOperands::ID = 0; 49*0b57cec5SDimitry Andric INITIALIZE_PASS(WebAssemblySetP2AlignOperands, DEBUG_TYPE, 50*0b57cec5SDimitry Andric "Set the p2align operands for WebAssembly loads and stores", 51*0b57cec5SDimitry Andric false, false) 52*0b57cec5SDimitry Andric 53*0b57cec5SDimitry Andric FunctionPass *llvm::createWebAssemblySetP2AlignOperands() { 54*0b57cec5SDimitry Andric return new WebAssemblySetP2AlignOperands(); 55*0b57cec5SDimitry Andric } 56*0b57cec5SDimitry Andric 57*0b57cec5SDimitry Andric static void rewriteP2Align(MachineInstr &MI, unsigned OperandNo) { 58*0b57cec5SDimitry Andric assert(MI.getOperand(OperandNo).getImm() == 0 && 59*0b57cec5SDimitry Andric "ISel should set p2align operands to 0"); 60*0b57cec5SDimitry Andric assert(MI.hasOneMemOperand() && 61*0b57cec5SDimitry Andric "Load and store instructions have exactly one mem operand"); 62*0b57cec5SDimitry Andric assert((*MI.memoperands_begin())->getSize() == 63*0b57cec5SDimitry Andric (UINT64_C(1) << WebAssembly::GetDefaultP2Align(MI.getOpcode())) && 64*0b57cec5SDimitry Andric "Default p2align value should be natural"); 65*0b57cec5SDimitry Andric assert(MI.getDesc().OpInfo[OperandNo].OperandType == 66*0b57cec5SDimitry Andric WebAssembly::OPERAND_P2ALIGN && 67*0b57cec5SDimitry Andric "Load and store instructions should have a p2align operand"); 68*0b57cec5SDimitry Andric uint64_t P2Align = Log2_64((*MI.memoperands_begin())->getAlignment()); 69*0b57cec5SDimitry Andric 70*0b57cec5SDimitry Andric // WebAssembly does not currently support supernatural alignment. 71*0b57cec5SDimitry Andric P2Align = std::min(P2Align, 72*0b57cec5SDimitry Andric uint64_t(WebAssembly::GetDefaultP2Align(MI.getOpcode()))); 73*0b57cec5SDimitry Andric 74*0b57cec5SDimitry Andric MI.getOperand(OperandNo).setImm(P2Align); 75*0b57cec5SDimitry Andric } 76*0b57cec5SDimitry Andric 77*0b57cec5SDimitry Andric bool WebAssemblySetP2AlignOperands::runOnMachineFunction(MachineFunction &MF) { 78*0b57cec5SDimitry Andric LLVM_DEBUG({ 79*0b57cec5SDimitry Andric dbgs() << "********** Set p2align Operands **********\n" 80*0b57cec5SDimitry Andric << "********** Function: " << MF.getName() << '\n'; 81*0b57cec5SDimitry Andric }); 82*0b57cec5SDimitry Andric 83*0b57cec5SDimitry Andric bool Changed = false; 84*0b57cec5SDimitry Andric 85*0b57cec5SDimitry Andric for (auto &MBB : MF) { 86*0b57cec5SDimitry Andric for (auto &MI : MBB) { 87*0b57cec5SDimitry Andric int16_t P2AlignOpNum = WebAssembly::getNamedOperandIdx( 88*0b57cec5SDimitry Andric MI.getOpcode(), WebAssembly::OpName::p2align); 89*0b57cec5SDimitry Andric if (P2AlignOpNum != -1) { 90*0b57cec5SDimitry Andric rewriteP2Align(MI, P2AlignOpNum); 91*0b57cec5SDimitry Andric Changed = true; 92*0b57cec5SDimitry Andric } 93*0b57cec5SDimitry Andric } 94*0b57cec5SDimitry Andric } 95*0b57cec5SDimitry Andric 96*0b57cec5SDimitry Andric return Changed; 97*0b57cec5SDimitry Andric } 98